Improvement in dental drills



JOHN J. ROSS.

Improvement in Dental-Drills. No. 127,518. Patentedlune4,1872

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JOHN J. BOSS, OF MEMPHIS, TENNESSEE.

IMPROVEMENT IN DENTAL DRILLS.

Specification forming part of Letters Patent No. 127,518, dated June 4, 18772.

I, JOHN J. Ross, of the city of Memphis,

county of Shelby, and State of Tennessee, have invented certain Improvements in Drills, of which the following is a specification:

7 My invention consists in a combination of a reverse-acting spiral spring with a cord attachment, and a drive-wheel with a revolving axle, into the center of which the drill-bit is set, thus forming a drill to be used in dentistry, and all other work where drills are serviceable, and by means of which an operator may work in places not to be reached by other drills; reference being made to the accompanying drawing as part of this specification, in which- Figure l is a perspective view Fig. 2, sectional view.

A A is the handle or barrel of the instrument, and contains the spiral spring B B, which moves freely in barrel A A. D is the cord, one end of which is attached to the spring at F, passing thence through the coil of the spring and the hollow arm 0, over the drive-wheel O, and out through an opening, X, the detached end hangin g outside, and being long enough to be grasped securely by the operator. 0 is the arm, one end of which, be ing screwed into the handle A A at H, holds the end of the spiral spring, which rests against it firmly when the opposite end is drawn up by pulling the cord in working the instrument. In the head of this arm 0 is the drive-wheel G, inclosed or otherwise, which has a groove, around it, and is operated by the cord, being drawn out by the hand, which revolves the wheel in one direction, and the spring, drawing the cord back, revolves it in an opposite direction. The center of the wheel projects through the side of the arm head, in the form of an axle, and has a receptacle for the drill-bits from each side, the bits being held firmly by means of screw-threads or otherwise.

I claim as my invention- The"combination of the barrel A A, spring B B, cord D, and wheel (has described, and for the purpose herein set forth.

JOHN J. ROSS.

Witnesses: v JOHN E. FINLEY, B. F. TATEM. 

